Lessons in Love: a sequel
by bluesnowflake44
Summary: Please read my fic "Lessons in Love" first! Thanks. : Now that Casey knows a thing or two about the art of flirting Derek style , she feels the need to put her newfound knowledge to good use. Complete.
1. Chapter 1

Lessons in Love: Respect and Responsibility

Lessons in Love: Respect and Responsibility

A/N: Aww, thank you to everyone who reviewed and favorited "Lessons in Love"! I squee at reviews of any kind, so please- keep them coming. Since many people expressed an interest in a sequel, I am happy to present just that! It was a lot harder to write, for whatever reason, but I hope you enjoy it. :)

SUMMARY: Now that Casey knows a thing or two about the art of flirting (Derek style), she feels the need to put her newfound knowledge to good use.

Chapter 1

"So," Casey seethed at a certain stepbrother, "it's not enough that you have to empty the entire ketchup bottle on me… but you also feel the need to douse my hair with mayonnaise?" She threw a broccoli stem at him from across the dinner table, but Derek dodged it easily. "What's next? Mustard down my shirt?"

"Of course not." Derek waved a hand lazily in dismissal. "I hate mustard."

"Guys, guys," soothed Nora. "Let's try to have a nice, family dinner, ok?"

"There's nothing NICE about Derek!" Casey spat.

"Yeah, and there's nothing remotely family-like about this," Derek added.

"Look," George said, "Please, if you won't do it for your Nora or my sake, please try to set a good example for Marti, ok?"

"Hey!" Marti squeaked from somewhere below the table. "Derek isn't a good example! He taught Daphne how to—"

"Okay!" Derek hastily interrupted. "Truce, Case?"

Casey just rolled her eyes at him. A bit of flirting and a kiss or two didn't change anything between them. He was just as annoying as before….

"Yeah, whatever, Derek. No truce is going to help with whatever it is you have against me."

"Oh, that's coming from the girl who likes to boss me around every chance she gets, like the control freak she is?"

"Enough!" George yelled. "You two" he motioned at both Derek and Casey, "upstairs, NOW. You're staying in your rooms until you can learn to respect each other."

Casey slammed her glass of water down. Fury rose within her, and she barely noticed Lizzie scoot several inches away from her. "I can't BELIEVE that you're asking _me_ to take the punishment again! Derek started it all with his ketchup-spraying frenzy."

"Well, honey, why don't you be the one to finish it then?" Nora gave her a quick smile. Casey opened her mouth to refuse, but caught Derek's eye. He was smirking at her, one eyebrow slightly raised. Suddenly he jumped up from his seat and went upstairs.

"Fine," Casey replied. She rose, cleared her dishes, and stomped upstairs, still furious, yet also undeniably curious. What was on Derek's mind?

She reached the top of the stairs, expecting to find Derek waiting for her at his bedroom door, a "come-hither" look on his face. Instead, his door was closed, its red paint glaring at her with a smug sheen under the fluorescent lighting.

"Hmph." Casey made a face at the door and waltzed by it. She didn't care about Derek or any of his stupid lessons. And anyways, they were all just completely… _stupid_.

She flopped onto her bed, considering what she wanted to do. To her extreme annoyance, she couldn't banish the image of Derek sprawled out across his bed, just a few yards away, his hair falling into his eyes and his long legs stretched tantalizingly—

"Pajamas!" Casey shrieked to herself. That was a good way to distract herself. She ignored the fact that it would be a very brief distraction. _One step at a time…_

She pulled her sweater over her head and reached back to unfasten her bra. It was stuck. Frowning, she tried to twist her arm around to get a better angle.

"Need some help?" a voice asked her to her left. Casey screamed, her hands dropping from her bra and crossing her chest quicker than lightning. Panicked, she glanced over, but all she saw was her closet. A low snickering, however, gave away Derek's hiding spot.

"_Are you spying on me_?" she demanded, livid with rage. She yanked open her closet and found Derek wedged in its corner. He flashed her a mischievous grin.

"Just wanted to see if we're the same shoe size," he said, completely serious. "I was hoping to borrow a pair of yours for the upcoming prom!"

"De-REK!" Casey screeched, and Derek burst into laughter.

"Oh my God, you should have seen your face!" He collapsed onto her bed in spasms of laughter, clutching his sides.

"Oh really?" snarled Casey, her voice dripping with sarcasm. "Which part? When you watched me undress or when you claimed to be a cross-dresser?"

Derek paused in his laughter, pretending to seriously consider her question. "Both, actually. Although I have to say the view was – to my great disappointment – cut short during the first part." He rose from the bed and sauntered over to her side. "Care to continue?" he asked, leaning toward her ear. His breath fluttered the hair at her neck and sent a shiver down Casey's spine.

"NO!" she dashed away to sit on her bed. "And somehow I don't think this is what your father meant when he told us to learn to respect each other."

Derek looked chagrined. "You're right," he sighed. Casey raised an eyebrow. Derek plopped down next to her on the bed. "I should have asked you sooner if you needed help with that bra."

Casey whacked him with a stray stuffed animal. "You are _un-be-LIEV-able_!" she hissed.

Derek grinned. "You've got that right." He smirked to himself, then faced her with a wide grin, his brown eyes twinkling in a way that Santa Claus's might when he discovers a cake waiting for him instead of a tray of cookies. "So… you gonna teach me a lesson?"

Casey could only blink at him. _Did I hear that right?_ She asked herself. Daring a look at Derek, Casey realized that he was very serious… and very close to her. She gulped. How did he keep doing that? Invading her personal space without her realizing it was an _invasion_?

"Wh-what?" Casey stammered.

"I said," Derek repeated, "Do you wanna teach me a lesson?" His gaze lingered pointedly at her chest.

Casey bristled and crossed her arms again. "And what lesson would that be?"

Derek only smiled, his lips tugging upwards lazily as he probably imagined all sorts of disgusting things. Casey grimaced in disgust. She was livid that he was viewing her the same as any and every girl: as a body with boobs.

"Well," Casey replied, slowly and deliberately, as if speaking to Marti (_although no conversation with Marti would follow this train of thought_, Casey thought to herself), "We could start by learning about proper respect. Your dad had a point when he wanted us to learn to respect each other."

Derek groaned and flopped onto his back on her bed. "You sure know how to ruin the mood," he muttered darkly at towards the ceiling.

"Well, sor-RY!" Casey spat, more stung at his accusation than she cared to admit. "But if you want to get anywhere with me, you have to respect me and respect my fellow gender."

Sitting up, Derek raised his eyebrows at her. "Who says I want to go anywhere with you?" His sly smile was back. "You're the one who stripped to her bra." He got up and waltzed to her dresser, opened it, and held up a turquoise bra with one finger. "And, really, Casey? I never would have guessed your size!" He examined the bra's tag. "You really should wear tighter shirts. Wear your endorsements with pride."

Casey – who had been sitting with her jaw open in speechlessness – snapped out of her shock and gave Derek a shove. It barely even moved him.

"I can't believe you just said that to me! That is so rude, Derek!" She gave him another, more forceful shove, sending him toppling from her bed. Casey started to smirk herself, but then she realized that Derek had grabbed her wrists and she was falling with him off the bed…

--

"OOF," Casey groaned as they hit the hard floor. They landed in a tangle of limbs and skin and – Derek forgot how to breathe for a moment as Casey's hair fell over his face. It smelled like lavender and tickled his lips. "DEREK!" Casey's voice screeched in his ear. "I could have DIED!"

Rolling his eyes at her dramatics, Derek tried to straighten himself, ignoring the way that Casey's chest was pressed into his knee. He felt a brief, familiar twinge deep in his gut at the feeling of so much of Casey's exposed skin touching him. The thin cotton of his t-shirt wasn't much protection.

"You'll be fine, Klutzilla," he managed to half-choke out. God, sometimes he _hated_ being a guy….

"Yeah, no thanks to you!" Casey's eyes snapped dangerously at him. He couldn't help grinning back at her.

"You know you wanted this," he replied, lowering his voice a notch for effect. It obviously had the right effect; Casey's face had a taken on a rosy tint and her chest – _her chest –_ had started to rise and fall with her quickened breathing. Her bra, he was fascinated to note, was just a simple, pale pink thing – no frills or lace or anything fancy about it. And yet, it captivated him – almost as much as the way it curved around her boobs did. He really wanted to just snap it off her. They'd come close yesterday, he reminded himself, but after he'd doused her in ketchup before dinner she hadn't wanted to "study" anymore. He only hoped that his plan would work.

"You wish," Casey said, but her voice was a bit shaky. Derek leaned closer to her, hoping to catch her off guard with a kiss. When his lips pressed against something soft and… _fuzzy_?... he drew back in revulsion.

"What the hell happened to your—" he cut himself off as he saw what he'd almost started to make out with. "YOUR TEDDY BEAR?"

Casey gave a bark of laughter. "That's what you get if you think you can just kiss me whenever you want to. Mr. Fuzzy Muffins does not approve of unchaperoned behavior between two members of the opposite gender." She shoved the stuffed animal into his neck and pretended to make it snuggle up against him. "You're going to have to learn a few of _my_ lessons, Derek."

"First of all," Derek made a face of disgust at the teddy bear, "Never mention that thing's name to me again. Second of all: _Ew_. You've got a sick sense of humor, Case. I mean, after all those times you just 'burst in' during my special couch time, I figured you were into _watching_ me, but I never knew you fantasized about me and inanimate objects!"

That brought a squeal of protest from Casey. "Oh my God, Derek! You are a disgusting pig!"

"Thanks," Derek flashed her a smile. But despite the grin he gave her, he couldn't help feel disappointed in how this evening was turning out. _And with Casey practically half-naked, too,_ he thought. _Dammit_.

"Out!" cried Casey. "Out of my room NOW!"

"Fine, fine," Derek muttered, rising and walking to the door. "Good luck getting the bra off," he snapped, leaving the room. "Let me know if you change your mind about needing help!"

The door slammed behind him.

--

It was 9am on a Saturday, but Casey had a long day ahead of her. After Derek had stormed out (upset that he didn't get his way), she'd spent the past evening hatching a plan. Thanks to Derek's _tutoring_ from the other day, Casey had a few ideas about the art of flirting and putting her femininity to good use. She knew that she had a certain appeal to Derek (why would he have tried to kiss her again last night?), and Casey had decided to put that appeal to good use. It was time to teach Derek a lesson of her own. He's had the upper hand in this household for the past 5 months; now it was definitely her turn.

She glanced down at the brainstorm list she'd come up with the night before, of all the things about her (and women in general) that made Derek squirm with pleasure:

_1. Perfume_

_2. Hair_

_3. Lips_

_4. Breasts_

Pretty much anything attached to a female would work on Derek. She felt blessed at her good fortune in that regard. That many more things she had against him! She smiled to herself, and chewed her lower lip in thought. _What kind of things can I get out of him?_ she wondered. She didn't just want to make her… "lessons" about simple day-to-day matters, like having him wash the dishes for a week or do her laundry or anything boring like that. This had to be good. She wondered how far he would go for a thing or two on her list….

Casey had a plan. With each request she asked of him, and every lesson she ingrained into his head, she would offer him a reward, a bribe. With Derek, you couldn't just ask him nicely and expect him to obey out of the kindness of his heart. Derek needed something else, and extra incentive, if you would. That's why she'd planned out four different lessons with four different rewards. Rewards that were very much connected to a certain stepsister he seemed keen on getting a bit more intimate with. _Well_, Casey snickered to herself, _in my book, it's work before play for good old Derek_. She glanced down at her list with an impish glee. _And for me… a well-deserved vacation!_

A/N: Now the plot is REALLY going to pick up and get juicy, if you haven't already guessed. Hope you liked chapter 1. :)


	2. Chapter 2

Lessons in Love: Respect and Responsibility

Lessons in Love: Respect and Responsibility

A/N: Here's the next installment! This story is going to be a bit ridiculous (lol), but a lot of fun (at the very least, I'm having fun writing it!) Thanks for your reviews, and I'm glad you're enjoying the story. If you have any suggestions or things you'd like to see happen, I love ideas and feedback!

Oh, and as for when this story takes place… I imagine it as around the middle of season 2. Although the "Life with Derek" timeline is so screwed up, that it's kind of tough to figure it out. Just know that it takes place a bit in the past (pre-Sally and Max. I didn't even want to think about them… talk about happiness-ruiners!).

Chapter 2

"Done!" Casey said to herself. She beamed down at her list, feeling very pleased with the progress she had made. With each reward, she mused happily, came a lesson in love. But not lessons in love _Derek_ style. A small tingle danced along her skin at the memory. She shook her head in an attempt to rid herself of the memories. No, she mused, this would go _her_ way. Derek may have taught her a thing or two about flirting and kissing and… other things (Casey pretended that the blush she felt at the memory was only because she was pleased with how much she had learned…). But now it was her turn to teach _him_ a thing or two… starting with his treatment of women!

"It's just about perfect!" she said to herself with glee.

Her bedroom door opened and Derek strolled in. "Whatever could you mean?" he asked, plopping down in her desk chair. "Making lists, I see, as usual?"

"Derek!" Casey hissed, attempting to hide the notebook pad. "Were you listening in?" He only smirked in response. "Well, if you must know," she huffed, rolling her eyes at his inability to grasp the concept of knocking, "I _am_ making a list. And it's a very important list." She smirked up at him. "It involves _you_."

This caught his interest immediately, although she was amused to see that he tried to play the nonchalant card. "Oh really?" he asked, scooting the chair closer to her. "What sort of… 'involvement'… are we talking, here?" he added, raising an eyebrow suggestively.

Casey rolled her eyes again. "Real mature, Derek," she spat out in sarcasm, then sighed. Would Derek ever take her seriously? "You know how you asked me if I wanted to teach you a lesson?"

"Yeah," he said, the start of an impish smirk tugging at the corner of his lips.

"Well, I thought of a lesson to teach you."

"Oh really?" he asked, a full-blown smirk pulling one side of his mouth upwards and crinkling his eyes at the corners.

"Yes. We're going to go through the different stages of a date. You need to learn how to treat a girl with kindness…. —And stop rolling your eyes at me, Derek! You told me what a _guy_ expects out of a girl with flirting and… all that," Casey scowled as she felt her blush return at the memory of his mouth hot against her own. It was so difficult to concentrate on the task at hand when he was grinning at her from such a short distance! "So I was just thinking," she went on, smoothing her shirt in an effort to refocus her thoughts, "that I could teach you a thing or two about what a girl expects, and about her needs.

"Now," she continued, "First things first. You've got to compliment a girl on how she looks. That comes before anything else when you're with her. And no viewing girls simply as _things_."

"May I speak?" Derek asked, glaring at her. When she grudgingly nodded, he placed a hand upon his chest and said, "I would never view a girl as a 'thing.' She's much more important than that."

"Good, good!" Casey beamed. "You're learning already!"  
But Derek didn't appear to be done. He leaned closer to her, his face coming nearer and nearer to her own, and Casey found herself struggling to catch her breath. As soon as she felt his hot breath whoosh against her cheek, her body started acting on its own: her eyes fluttered closed and her lips parted. But nothing happened. She popped her eyes back open only to see Derek had completely disappeared.

"Wh—" she started to ask, blinking in confusion. Derek was gone. Casey screeched in anger, bellowing, "DEREK! GET BACK HERE! WE HAVEN'T FINISHED YET!"

She leapt up from her bed and burst out of her room, leaving her notepad forgotten on her bed…

--

Laughing to himself, Derek sprinted to the bathroom and locked the door. He knew that Casey was up to something, and he planned on getting the upper hand. He did admit that it had been a little tempting to kiss her just then, but he was Derek Venturi, after all – he was so damn sexy that it was even difficult for him to resist himself sometimes. A moment later, a loud knocking sound was heard on the door.

"Derek!" Casey's voice insisted. "Let me in! We're not through with even the very first lesson! You can't escape that easily!"

"Oh, I think I just did!" he called back, leaning against the door and snickering. "Unless you want to come in here with me while I take a shower?"

The knocking ceased immediately. "N-no thank you," Casey replied. "I'll just go do some homework downstairs and… far away…."

Smirking to himself, Derek resisted the urge to rub his hands together with glee. He waited a few minutes until he was sure that she was gone, and then carefully unlocked and opened the door. Casey was nowhere in sight, so Derek snuck out and crept into her room.

"Where is it?" he asked himself, looking around. His eyes fell upon a notepad lying on Casey's bed. Grinning, Derek swiped it and darted back to the bathroom. This was going to be too easy….

He opened the first page and furrowed his eyebrows. The page in front of him read:

_1. Perfume_

_2. Hair_

_3. Lips_

_4. Breasts_

"What the hell?" he mumbled to himself. Deliberating for a moment, he finally decided that he didn't even want to go there. Flipping over the next page, he came across the word "PLAN" written at the top. This looked good. Much more promising than the last page….

_Trick Derek into learning the rules about the considerate and proper dating of the female sex._ (Derek couldn't help snickering at the last word – "sex! Haha!"). _Use rewards for him that pertain to the previous list so as to encourage and promote the desired behavior._

"Who writes their notes like this?" he muttered, making a face at the words. "She doesn't even use shorthand!" He continued reading.

_First lesson: Teach Derek the appropriateness of complimenting a woman's appearance. Reinforce—_ ("Reinforce?!" he cried, outraged. "Am I a dog now?") _—the importance of this by exposing him to the scent of female perfume for positive emphasis._

"Okay, McDonald," Derek seethed. "How about I show _you_ some positive reinforcement?" He looked up from the page and glanced around the bathroom wildly, and his eyes landed upon a bottle of the body spray that Kendra had once bought him for their first-month anniversary. He'd worn it all the time when they'd been dating, but since then had forgotten about it. Well, it was time to put it to good use again….

--

"Carry the 3, then multiply the -2x by 4y… Let's see, that would equal -6xy…. No, no, wait! It would be—" Casey threw her pencil onto her paper and huffed in annoyance. She couldn't concentrate! All she could think about was Derek. Derek leaning in to kiss her, Derek's lopsided smirk, Derek taking a shower….

"No!" Casey gasped, and snatched up her pencil again, trying to remember how to solve the algebra problem in front of her.

"Sounds pretty gruesome in there," Lizzie said, entering from the kitchen with a glass of milk. She clutched a soccer ball in the other hand. "Working on homework?"

"Yeah," Casey replied. "But it's pretty difficult. I can't seem to… to figure it out."

"Hmmm," Lizzie said, sitting next to Casey and setting her milk on the dining room table. "Well, I'm definitely not as advanced in math as you are, but I could give you a few of the tips that I use." Casey nodded, and Lizzie continued. "First you have to consider the problem. What needs to be done? What are the factors in it? What exactly are you dealing with?"

"Right, right," Casey replied, thinking of a certain step-brother.

"Then you have to figure out what approach to take to it," Lizzie went on. "Is there a missing variable? Or do you simply need to find an answer?"

Casey nodded vigorously. _Yeah,_ she thought to herself_, Yeah, maybe I'm approaching this Derek thing all wrong. Maybe there's a missing variable in here somewhere…._

"And finally you just dive right in, and make sure you solve for x!" Lizzie finished triumphantly.

_Yeah, yeah, that could— _"Wait, what?" Casey asked, her eyebrows furrowing in confusion. "What does the 'x' have to do with anything?"

Lizzie raised her eyebrows, giving Casey a weird look. "We _are_ talking about math homework, right? And aren't you in algebra?"

Casey paused, and then gave a nervous laugh. "Oh, oh yeah! Haha, that's right! I knew what you meant, I just forgot that the x was…" she trailed off at Lizzie's expression.

"Still pining over Sam?"

Casey gave her younger sister a blank look. "Uh," she finally replied. "Uh, yeah. Yeah! That's it, that's it exactly!"

Lizzie just rolled her eyes. "I don't think I even want to know what's going through your head right now."

Since Casey's mind had just been imagining the previous night's make-out session with Derek, Casey had to agree with her younger sister. _What am I getting myself into?_ she wondered. _What would people even _think_ if they knew about Derek and me?_

The front door opened. "Yo," came Edwin's voice. "How's life at the ol' McDonald/Venturi homestead?" He set an oddly-shaped metal box onto the table next to them. "Doing homework, are we?"

Casey and Lizzie stared at his box. "What's that?"

"This?" Edwin gestured towards it. "This is _only_ going to be my retirement fund! It's genius, I tell you, genius. I bought it at the store next to school." He popped open the lid. "See? It's a magic kit!"

There was a pause, then Lizzie replied, "A magic kit… like all the other ones you've had and claimed would make you rich?"

"Haha, Lizzie," Edwin threw her a thanks-for-your-enthusiasm grin. "No. This is a magic kit that's aimed for adults, like myself. Well, I could pass," he added at Casey and Lizzie's skeptical expressions. "It involves the difficult art of chemical mixing!"

"You mean _chemistry_, oh brilliant one?" Lizzie raised an eyebrow. Edwin ignored her comment.

"That… that's great, Edwin," Casey forced enthusiasm.

"Thanks, Casey," Edwin grinned. "Hey, Lizzie, wanna be my assistant?"

Casey just shook her head, but found she couldn't help smiling. At least she was distracted from certain… people now. That was always a plus when she hung out with Lizzie and Edwin. They sure were two-of-a-kind.

"Edwin," a voice from upstairs yelled. "Laundry, NOW."

Edwin sighed, looking slightly crestfallen. "Gotta go, guys. Duty calls."

"Don't you mean, 'Derek calls'?" Lizzie challenged.

A smile reappeared on Edwin's face at his step-sister's joke. "You're right, Liz. So… wanna help me with laundry?"

Lizzie shrugged, but Casey noticed a small smile on her lips. "Sure, it beats helping Casey with her _algebra_."

They trudged upstairs to get the laundry basket Derek was holding at the top of the stairs.

"Hey, Case!" he called once Lizzie and Edwin had disappeared into the laundry room together. "C'mere!"

Pushing down a sense of anticipation, Casey rolled her eyes and set aside her half-forgotten homework. "Ok!" she called back, pulling her perfume out of her purse and spraying it onto her neck and wrists. _Now, just remember_, she told herself, taking deep, calming breaths. _You can do this! Just don't forget to pay attention to variables, and always solve for x!_

--

"Where are you?" Casey's voice floated from the stair landing. Derek grinned to himself, waiting for the perfect moment to attack.

"Derek?" He heard her footsteps thump a few feet closer, then yanked open the door and pulled Casey in close to him.

"DEREK!" Casey squeaked. "What are you doing?"

He placed a finger on her lips. "Continuing our lesson, of course, genius. What else?"

"Does it have to be continued in the closet?" she hissed.

Chuckling, he replied, "Where else did you have in mind? The shower, perhaps?"

He felt what could only be Casey's fist punch him in the arm. "Oooh, ow, Casey. You've really hurt me with your incredible strength."

"Shut up," Casey snapped, taking a step closer to him in the darkened space. "Now let me out, I'm leaving this inst—" But she stopped mid-sentence as he stepped directly in front of her.

Derek grinned. "You were saying?"

The silence continued.

"Are you, Casey McDonald – the grade-grubbing, bad-idea-spewing, stair-tripping freak – actually rendered speechless by _me_?" He felt an electric tingle travel down his spine at the thought and his mouth grow dry in his body's anticipation. He cleared his throat.

This seemed to awaken Casey from her stupor. "Never!" she snapped. "I was only a bit surprised at your sudden choice of… aftershave, is all." He heard her swallow. "But it was just a brief moment of temporary confusion, nothing more."

"Do you like it?" Derek asked, lowering his voice a notch and reaching up to trail a finger along the bare skin on her arm.

"Nnnnnnggghhh" Casey murmured, leaning into him. "Carry the x!" she squeaked out at last.

Derek's hand paused, mid-stroke. "What?" he asked. "Did I just hear you make a _math_ reference?"

"No! ……" She sighed as he wrapped a hand around her waist. "The stupid x is failing me."

Derek took a step closer. "I thought you never failed anything?" he asked.

"I don't," was her reply (although, he gleefully observed, her voice sounded a bit strangled). He leaned down so that their mouths were almost touching, and felt his body react to the hot (if somewhat hyperventilating) breath of Casey McDonald.

His hands tightened around her waist, "accidentally" nudging her shirt up and caressing her skin with his fingertips. Their faces were so close he could taste the lavender perfume radiating off of Casey's skin. He leaned his face into her neck and pressed his lips below her ear. Inhaling the intoxicating scent of his skin, he felt his pulse speed up as all his blood rushed downwards….

Suddenly a sharp push sent him stumbling backwards a step. "What the hell?" he growled. "Casey! The—we—what about the lesson?"

The light snapped on, causing Derek to blink. Casey was smirking up at him. "Ah, ah, ah!" she reprimanded, wagging a finger in front of him. "You're not allowed to have dessert before dinner, Derek."

He could only continue blinking. "What the hell are you talking about?"

"We haven't talked about payment yet."

"Payment?" Derek cried. "I thought _I_ was paying _you!_ That's the only reason I'm wearing this damn smelly stuff!"

Casey rolled her eyes. "Yeah, but you forgot about the variables." At his incredulous expression, she raised an eyebrow and glanced pointedly at his crotch, and said, "You let your hormones get away with you."

Derek felt his jaw fall open as she pushed past him, opened the door and exited. She leaned out of her doorway and gave him a huge smile. "Close your mouth, Derek; it's not polite to gape at people who are smarter than you." She gave him a wink, and added, "When you're ready to continue our lessons, you know where to find me."

_That… that…_ Derek gave up trying to think of a name for the force that was his stepsister. _Oh, it is SO on, Casey_. He'd get her back for that. This was far from the end….

A/N: Hope you all enjoyed! Lol, I totally worked on this while watching one of my favorite Life with Derek episodes ("Don't Take a Tip from Me"). Lol, such a funny Dasey-filled episode. And I totally forgot that Derek actually owns body spray, so that worked perfectly for the story!


	3. Chapter 3

Lessons

Lessons in Love: Respect and Responsibility

A/N: Ooooh, so how exciting was the first episode from Season 4? I personally thought it was adorable. Sure, there could have been more Dasey, but what about the hula-hoop moment? Classic Dasey. Anyways… about my fic: I totally made up all of Edwin's magic tricks, so yeah… just go with me about that, ok? ;) Thanks for the reviews, and I'm glad you're enjoying the story!

Chapter 3

"Presenting the charming, witty, and gifted Edwin Venturi." Lizzie stifled a yawn of boredom. It was late Thursday afternoon. Edwin was making them all practice his big entrance when he performed his magic trick for the family later the next weekend. Nora had informed them that her sister and her sister's family were driving up to visit them for the weekend, and Edwin wanted to be sure his act was perfect for Victoria.

"A little more enthusiasm, if you don't mind," Edwin said to Lizzie. "And you forgot 'fabulous', Liz."

Rolling her eyes, Lizzie plastered on a fake smile, "Presenting the charming, witty, and gifted Edwin Venturi, who – don't forget – happens to be absolutely _fabulous_!"

Casey smiled at Lizzie's obvious mockery, but Edwin basked in the glory. "Now we're talking, now we're talking!" He turned to Marti, "Ok, so now you'd roll in the table with the chemicals, got it?"

Marti pouted. "But I want to be your assistant! Why does Lizzie get to help you mix things?"

Edwin sighed in response. "Lizzie is older, Marti, and she won't knock anything over."

Marti looked like she was on the verge of tears, so Derek stepped in. "Marti, remember when Edwin let you play with his magic tricks on your fifth birthday party? Remember when you dumped the blue ink all over him and it looked like he peed blue? _That_'s why he wants Lizzie to help him. Otherwise you'd out-do him in the humor department."

Marti giggled with glee. "HEEHEE! Edwin peed blue!!"

Shooting Derek a look, Edwin thumped his magic wand on the table. "Order, order! Ladies and gentlemen, can we please continue with the magic show rehearsal?"

He raised his eyebrows at Lizzie, who sighed and continued. "Wizard Venturi will now make a mini fireworks display with the magic of his potion shop!"

"It's _Magician_ Venturi, Lizzie," Edwin cried. "How many times do I have to remind you? Victoria will never be impressed with my incredible talent if you completely screw up the introduction!"

"UGH," Lizzie groaned. "This is stupid, Edwin. Who cares if you can make a few lousy fireworks sputter out of a beaker?" Glaring, she started stomping upstairs, then paused. "Go find yourself another assistant: I QUIT!"

"Oh dear," Edwin mumbled as Lizzie disappeared.

"Well, smooth going, Ed," Derek drawled. "You've really blown your already-slim chances with the ladies now."

Edwin stomped upstairs, ignoring Derek and mumbling something about the high standards of audiences everywhere.

"Well, smooth going, Derek," Casey mocked Derek's earlier words. "Now you've crushed all of Edwin's dreams."

"Hey! I wasn't the one who quit on him. I believe that was _your_ side of the family."

"Lizzie was just tired of being treated unfairly!" Casey yelled. "Edwin should have known better than to have assumed she would do whatever he wanted without proper gratitude!"

"Yeah, well Lizzie should learn to take what she can get!" Derek's mouth was pressed into a thin line. Both he and Casey were breathing hard, and Casey's hands trembled with fury. Neither spoke for a moment.

"Um, you guys?" Marti spoke up for the first time. Casey jumped; she'd forgotten all about Marti. Even Derek looked surprised to see his sister standing there next to them, looking back and forth between them. "Who exactly are you talking about?" she asked in all innocence.

Neither Derek nor Casey responded for a second, until Casey said (eyes still locked with Derek's), "I'm referring to a very immature, very selfish human being, who doesn't care a thing about other people's feelings."

Derek's eyes narrowed in response, and he said, "And I'm referring to a self-centered person who always expects way too much from everyone and never understands why she's always so disappointed with the world." He paused, still glaring at her, then added, "At least when Victoria gets here I'll have someone mature to hang out with."

Casey gave a small gasp, then huffed in extreme annoyance. Derek's words had stung her, far more so than she cared to admit. Derek was behaving so immaturely! Had it really just been a few days since he had taught her about the art of flirting? Casey couldn't believe it.

"I don't know why I even try to get through to you," she snapped. "Vicky's way more annoying and immature than I am!"

"It's 'Victoria' now, remember?" Derek snapped back.

Casey took a deep, shaky breath, then spun on her heel and ran upstairs, without looking back even once. She managed to hold back the tears until she'd made it into her room and locked the door. _Derek is so mean to me!_ she thought as she pressed her face into her pillow to muffle her sobs. _I hate him!_

But even as she thought such ideas, she couldn't push the nagging feeling that what she _really_ hated wasn't Derek at all….

--

"Damned princess," Derek mumbled to himself as he stalked up to his own room. He couldn't wait until school was over the next morning and Victoria would arrive. He could use a good make-out session that was free of any complicated restrictions or required gratitude, or whatever it was that Casey wanted. Maybe Victoria would even side with him against Casey; he wasn't sure how the two cousins felt about each other these days. Derek shut his door and plopped onto his bed, hugging a pillow against his chest. _Hope she drives Casey crazy_, he thought angrily.

Just then Nora's voice floated upstairs, announcing that dinner was ready. Derek considered remaining in his room to avoid seeing Casey again, but his stomach rumbled loudly. He got up and went downstairs.

"I've made a special treat today for everybody, since I know this weekend will be hectic with Fiona and Vicky here. So eat up and enjoy!" Nora smiled and set a huge bowl onto the table.

"Yummy!" Marti chirped happily. "You're the best, Nora!"

"Aww, thank you, Marti," Nora replied, ruffling Marti's hair.

"Mom?" Lizzie asked. "Where is everyone going to be sleeping this weekend?"

Nora paused in the middle of scooping a pile of mac and cheese onto Edwin's plate. "Well, sweetie, George and I talked about it, and we decided that you and Casey could both sleep in your room. That way, Fiona can sleep in Casey's room. And Vicky will be sleeping on the couch in the living room. Does that sound ok?"

"NO," came a voice from the stairs, "It does NOT sound ok!" Casey appeared, looking livid. "Why do Lizzie and I always have to sacrifice? Why can't Derek give up _his_ room?"

"Because, Casey, Derek's room isn't exactly… a place that Fiona would want to sleep in." She paused and gave Derek a stern look. "But he _will_ have to clean up a bit before they arrive tomorrow."

Derek waited for an eruption, but Casey didn't reply. She just pursed her lips and sank angrily into her chair. Derek watched her for a moment, and saw that she looked quite disheveled; her hair was tangled and her face looked splotchy. God, she hadn't been crying over him, had she? It was so like her. Casey just couldn't take any negative observation about herself. Nobody saw him sobbing over what she'd said about _him_?

Casey glanced up at him as she waited for her turn to serve herself some cooked carrots. Derek rolled his eyes and looked away. He felt something soft and hot bounce off his arm. A roll lay in his lap. Casey had thrown it at him. Fuming, Derek chucked a spoonful of macaroni and cheese at Casey; it landed on her shirt.

Gasping in anger, Casey's eyes met his, their gaze challenging, and she lifted her water glass and splashed him (and half the table) with its contents. Derek had just picked up his own glass when George's voice insisted on order. "DEREK! CASEY! Stop your immature food fights _now_!"

Since George rarely raised his voice, his shouted command brought Derek out of his revenge-reverie and he paused. Casey lowered the spoon she'd been about to fling at Derek. "If you two can't at least _behave_ like mature adults for a few moments at the _dinner_ table, then you'll both have to face the consequences of missing dinner for the evening! Now you both need to go to your rooms this instant!"

Seeing that both George and Nora's faces were livid with rage, Derek decided not to argue. He set his glass down and rose from the table. Without a word, he went upstairs, hearing Casey's footsteps behind him. She tried to shove her way ahead of him, and Derek pushed her away. Casey staggered against the wall and gave a shriek of anger.

"De-REK!" she gasped, straightening up. "How could you? I could have broken something!"

Derek just ignored her and went into his room, sinking onto his bed and grabbing a magazine featuring the newest addition of women's bikini wear.

But Casey followed him, sputtering as she often did about this and that. He tried to continue ignoring her, flipping through the pages and admiring the bikini models, but Casey snatched the magazine out of his hands.

"Give it back," he seethed, sitting up.

"_No_," she challenged, then glared down at the shiny pages. "How can you stand to look at this stuff? It's completely misogynistic!"

Derek crossed his arms. "No, it's not!" Not that he had any idea what the hell that word meant…

She raised an eyebrow. "Do you even know what that means?"

_She knows me well_, he thought, then said, "I don't care. All I care about is that you give me back what's rightfully mine." He held out a hand, demanding the magazine back.

But Casey shook her head, her face brightening in the way it did when she had an idea. "No. Not unless you treat me with some respect." She backed toward his open doorway. "Now, come over here and apologize, then show me through the door and into my room like a true gentleman."

Derek couldn't help it; he burst out laughing. "I've always had my suspicions, Casey, but seriously: are you_ crazy_? I'm not apologizing to you about anything, especially not about something that was equally your fault. And I'm _definitely_ not showing you to your room."

"It doesn't matter that it was my fault, too. It's your responsibility to learn some chivalry!" She paused, then added with venom, "Maybe you can practice it on _Victoria_ tomorrow and earn an extra make-out session from her!"

Derek pretended to consider this. "Yeah… don't think so. I don't need to be chivalrous to get Victoria. She'll come willingly as soon as she finds out how hung up on me you are."

Casey's jaw clenched and she narrowed her eyes, looking angrier than Derek had ever seen her. Her hair was falling out of its French braid, and two spots of red appeared on her cheeks. "How – how _dare_ you make that assumption?" she sputtered. Then she held up the bikini magazine. Derek's eyes widened as he realized what she was about to do.

"Oh, don't even _think_ about it!" he cried, leaping up to grab the magazine before she could tear it in half, but it was too late. A loud, ripping noise filled the air and Casey threw the magazine in Derek's face.

"You need to learn some manners, Derek!" she yelled, glaring up at him, her eyes wide with the passion of her rage.

"Fine," Derek hissed. He held out a hand to show her out, and Casey's mouth quirked upwards in a satisfied smile.

"That's more like it," she said. Derek bit back an evil laugh as he prepared to trip her and send her sprawling over the threshold of his doorway. But then she tossed her hair over her shoulder, an eyebrow cocked at him as she started to brush past.

The scent of her hair filled his nose – it smelled like the lavender shampoo he had once filled with syrup, but even better. Derek forgot all about tripping Casey, he forgot about tricking her with his feigned good manners, he forgot about their earlier fight. He forgot about everything except for the way her hair fell loosely over her shoulder, the ends curling perfectly. He couldn't remember what he'd been planning – or even thinking about – before he'd caught a glimpse of the way her chestnut locks caught the yellow glow of the setting sun. As Casey started to leave, Derek reached out and grabbed her upper arm. She gave a startled gasp as he yanked her back inside his room and slammed the door shut.

"Derek, what are you doing—" But Casey never got to finish her question, which was a good thing because Derek honestly didn't know the answer to that. He pressed his mouth against hers, silencing all of her questions with a furious kiss….

--

Her pulse erupted in her ears, her wrists, her neck, her chest. The feeling of Derek's lips on her own sent Casey's nerves into a frenzied shock, and she found herself grabbing the back of his neck and kissing him right back. Her pent-up anger at him seethed to the surface, only making her kiss him that much more passionately. Everywhere that Derek's fingers grasped her skin – her waist, her back, her neck – she felt electric tingles dance along her body. Under her lips, Derek opened his mouth to kiss her more angrily than ever, shoving her against his door in his desire to release his emotions.

Just as Casey thought her knees were going to give out, Derek broke away, breathing heavily. Their eyes locked, and Casey found herself taking deep breaths in hopes of clearing the haze from her vision. A lock of Derek's auburn hair had fallen into his eyes, and Casey itched to brush it back in place.

"So," Derek drawled, a smirk forming on his face, "how were those for manners?"

Casey shrugged a shoulder, hoping to hide just how much his kiss had truly affected her. "Could have been better."

"Well, I doubt you could do any better yourself." Casey might have considered just rolling her eyes and shoving past him, but at this moment he shook his hair out of his eyes, and Casey found that she couldn't control herself. She grabbed him and shoved him forward.

"Oh, really?" was all she asked, her eyebrows raised, then she spun him around and pushed _him_ up against the door where she'd just been standing, and crushed her mouth to his.

It was the oddest feeling ever, initiating a kiss with Derek. She'd done this before with Sam, so she was expecting the same reaction – the initial hesitation, the moment of confusion. But with Derek, there was no hesitation or confusion. As soon as her lips met his, she felt his hands reach behind her neck and press her face closer, his mouth immediately opening. Casey couldn't help gasping in shock at Derek's instant reaction. There seemed to be a fury behind his eagerness, as if his rush of emotions were triggering the force of his kiss and his desire to bring her as close to him as possible. But even more surprising was the way that Casey's free-will seemed to have completely disappeared, allowing her body to take over and do as it pleased. Her legs moved closer to the door and against his own body, and her hands reached down under his shirt to lift it up, feeling the smooth panes of his stomach. She found herself gripping at his waist to hold herself up as her mouth moved to the pulse of his neck. God, his skin tasted delicious, like sweat and soap and… was that cinnamon? Casey couldn't stop the groan that escaped from her lips, only to realize that it was actually _Derek's_ groan….

--

Casey wrenched herself away from him, panting hard and not even trying to hide it. For a moment, neither of them said; they simply stood there, no longer touching.

Then, Casey spoke, feeling very smug with herself, "If you really wanted to demonstrate some proper manners, that was the way to do it."

Derek laid a hand against the door and above her head. "It was—" he stopped, his voice having come out all huskily. _What the hell is the matter with me?_ he wondered. Clearing his throat, he continued, "Well, for a beginner, you did a decent job."

Grinning, Casey tilted her head up at him and said sweetly, "So… about the payment?"

Derek groaned. Of _course_ Casey would demand payment for something that she should feel privileged to have experienced in the first place! "What sort of payment?" he demanded, his curiosity getting the best of him.

"Well, you know that party that Ralph is throwing on Saturday?"

"Yeah," growled Derek, not liking the sound of this.

"I want you to bring me along. Not as your date!" she quickly added at the look of horror on his face. "But just, you know, as a favor. Tell your friends whatever you want. Ok, not _anything_ you want, but, you know, make up an excuse for why you're bringing me if you have to."

Derek considered this. Her request hadn't been as excruciating as he'd thought it was going to be, but it was still going to be tough to keep his current reputation if all his friends knew that he'd brought his grade-grubbing, klutzilla stepsister along, even if it _was_ out of pity for her. But perhaps this proposal of hers had its perks, especially if Victoria was coming. There would be _plenty_ of opportunities to make Casey squirm….

"All right," he agreed.

Casey beamed, and actually clapped her hands together (she was _way_ too happy sometimes…). "Really?" she gasped with glee. "That's great, Derek! Thank you so much!" She started to reach out for a hug, but he held out his hands to protect himself.

"Hugging equals bad, Casey, remember?" She just laughed, still ecstatic about the idea of going to a socially important party.

"But," Derek added. "There's one catch."

All the perkiness disappeared, and Casey frowned at him. "What?" she asked flatly, raising her eyebrows.

"Victoria comes with us. We can't just leave and go have fun without her. She's out _guest_."

The fury returned to Casey's face in a scowl that would have scared off Death himself. "Over my dead body!" she shrieked, placing her hands on her hips.

Now it was Derek's turn to laugh. "I thought you and Vicky were best buddies these days!"

"Hardly," Casey scoffed, leaning towards him and jabbing a finger at his chest. "And that doesn't mean I want my spoiled cousin tagging along and ruining all my fun!"

"Well, take it or leave it, Case. But that's my final offer."

Casey continued to glare up at Derek, thinking. "Fine," she spat out at last. "But I'd better not have to be her babysitter!"

"I'm sure she can handle herself. Isn't she older than you, anyway?"

"By a _month_!"

"Well, there you go. She'll probably end up babysitting _you_!"

"DE-_REK_!!"

A/N: Hope you guys enjoyed that chapter. It was a lot of fun to write! Keep reviewing, that will make me very happy and want to update sooner! hint hint, wink wink :)


	4. Chapter 4

Lessons Basic Ideas for Casey to make Derek do:

Lessons in Love: Respect and Responsibility

A/N: Sorry it took me so long to update. I've been pretty busy lately. Thanks to everyone for their reviews! Enjoy. :)

Chapter 4

"Aw, you're getting all grown up!"

Victoria bent down and pinched Marti's cheeks in adoration, who scowled in return. Derek didn't even suppress a smirk as he watched Casey roll her eyes at her cousin. He loved it when she squirmed.

"Victoria!" Edwin sauntered over, waggling his eyebrows. "I can't believe it, but you're even prettier than before."

She laughed. "Thanks… Edwin, was it?"

The shorter boy beamed, nodding enthusiastically. "That's me, Edwin, the devilishly handsome, brilliant-minded, multi-talented—"

Derek cut him off before things could get even more painful. "Hey," he said simply, smiling.

"Hi," she replied, her eyes going soft and her lip pouting slightly as she stared up at him. "You've gotten taller."

"So've you." He admired her hair, which was long and curly. "Like the hair."

"Thanks. It's natural, you know," she purred, looking up at him through her lashes. "It's been a long time, Derek. I had such a… _enjoyable_ time getting to know you last time, hopefully we can continue that this visit." She raised an eyebrow suggestively.

Casey took a step forward and cut in before things could go any farther, "Gee, it's great to see you, Victoria!" Her face was slightly red with what Derek could only assume was annoyance. He full-out grinned, knowing that this weekend was going to pretty much be the best weekend of his life. Casey forced a smile at her cousin. "How are things at home?"

"Dull," Victoria replied, her expression annoyed at the interruption. "Mom's so lovey-dovey, it's sick. And I just broke up with the head soccer player." She studied a nail. "He was just so… _boring_. And all my friends said I could do so much better." Glancing up at Casey, she raised her eyebrows. "So, got a boyfriend yet?"

"No," Casey growled. "Well, I did, but…" She glanced at Derek. Her relationship with his best friend was uncharted territory for them now. Derek felt a sudden tug of… unpleasantness at the thought of Sam putting his hands all over Casey, kissing her the way that Derek had so recently started to enjoy doing….

He resisted the urge to squeeze his eyes shut and go, "_La la la la la_," in an effort to dispel the image of Sam and Casey. "They broke up," he said, ending the silence at last. "It was my best friend, and I really didn't appreciate losing my time for hanging out with him."

Victoria didn't even respond; she seemed to have lost interest already. "So," she asked, coming closer to him. "Are _you_ free?"

Derek stiffened; he couldn't help it. _What the hell is wrong with me_? he wondered. _A hot girl is obviously hitting on me, and I'm going all spazzy_. He was spared answering by the entrance of Lizzie.

"Hello, Victoria," she said coolly.

"Oh, hey Liz," Victoria responded, taking a step away from Derek and plastering a smile on her face. "How's my favorite little cousin?"

"Not so little anymore," was Lizzie's even colder response. If Derek didn't know any better, he would have said that Lizzie was angry at Victoria for something she'd done before she'd even arrived. Girls were so weird….

"No," Victoria conceded, her smiling fading, "I guess not." She shrugged her shoulders and the grin returned. "So, who's going to give me a house tour? I want to see if anything's changed since last year!" She waited, eyeing Derek expectantly.

"Wanna see my room?" he asked. "I put up a couple new posters last month…"

"Sure!" she cooed, grabbing his arm and practically dragging him upstairs. They arrived at his door and she yanked him inside, shutting it behind her.

"Thank God," she gasped, and rolled her eyes. "Sorry about Lizzie and Casey; they're really weird. I always avoid telling people that I'm related to them if I can help it." She sank onto Derek's bed and leaned back, smiling at him.

"I thought you and Casey were friends these days." Derek went to his desk chair and sat down. The last time he'd had a girl in here, it was Casey. He rubbed a hand on the arm rest, recalling what he'd done with Casey on it, the feel of her skin under his fingers, her soft lips molded against his own…. _Stoppit!_ his brain demanded, and Derek leapt out of the chair and went to sit next to Victoria.

"…and she's just sooooo spoiled, too," Victoria was saying. "Don't you think?" Derek watched her mouth as she spoke. It reminded him a lot of Casey's mouth; both girls had full, pink lips. "I mean, why does Casey think she can get away with every little thing? She isn't the center of the universe, after all! And who does she think she is," Victoria continued with venom, "_stealing_ your best friend out from under your nose!" Pausing, she turned to face him directly, trailing a finger along his arm. "_I_ would never do that to you. Casey's not nearly as experienced as you or I are, either, when it comes to how to _interact_ with members of the opposite sex."

As his mind rewound to the intense kisses that he'd shared with Casey the night before, Derek found he had to disagree. But he didn't like the way his mind was thinking these days (damned thing was interfering with his potential make-out time with Victoria!), so when she leaned closer and locked her hand around his wrist, Derek didn't complain. When she leaned closer and kissed him on the mouth, he even enjoyed the way her lips felt against his own, just as soft as Casey's were, even if they didn't tingle the same way as when he kissed Casey.

The door burst open and Derek panicked, shoving Victoria off of him. "Ow!" she shrieked. Seeing that it was only Edwin, Derek let out a hushed sigh of relief. He'd thought that someone else might have come up to "check" on him….

"Er, sorry to, uh, interrupt," Edwin stammered. "I just wanted to let you know, Victoria, that I've got a splendid magic show planned for you this Sunday night, if you're interested."

"Yeah, sure," Victoria muttered, giving Edwin a quick smile.

"Sorry again to interrupt; Derek, you can murder me later, ok?"

It took Derek a moment to figure out _why_ he'd want to murder his younger brother. "Oh," he said, catching on, and putting an angry look on his face. "Yeah, that's right Ed. Better stay away for the next half hour, _or else_!"

Edwin nodded fervently, and shut the door. "Only a half an hour?" Victoria pouted, facing Derek. "I was hoping we could get at least an hour in before that stupid cousin of mine decides to invade my privacy again."

"Well, you know," Derek replied, waving a hand in dismissal, "That's what I had to say to Edwin. So as not to arouse suspicion from anyone."

"Hmph. So what are the plans for this weekend?"

Derek grinned. "Well, there's this killer party tomorrow night, if you want to go. It's being hosted by one of my best friends."

"Sounds great!" Victoria beamed, clutching Derek's arm in excitement. "Are we going as dates?"

"Uh," Derek mumbled, unsure, "Well, I kinda promised Casey that I'd let her tag along, too. I hope that's ok. I sort of… _owed_ her. So she'll be there too. But don't worry, _you_'ll be the guest of honor." He flashed her his most charming grin, and saw her soften before his very eyes.

"All right, all right. So long as I don't have to be her babysitter. Ugh, it's so annoying being the older one; I'm _always_ in charge of the kids!" She shrugged. "But that's what happens when you're the most mature, I guess."

"Yeah," Derek replied. "Casey sure is handful." At a memory of his most recent make-out session with her, he grinned to himself, and muttered, "Trust me, I would know."

--

"Ok, Vicky, what outfit do you think I should wear?" Casey asked, eyebrows furrowed in worry. "The red turtleneck with the black skirt? Or the purple cardigan and the khaki shirt?" She held both shirts up in the bathroom doorway, where Victoria was doing her hair.

"Um, how about you learn some fashion sense. You don't wear turtlenecks or sweaters or khaki to parties. It just isn't _done_." Victoria sniffed as she curled a lock of hair. "And _don't_ call me Vicky."

"Oh, right, sorry. I always forget that kind of thing when I'm nervous. But I really should have nothing to be nervous _about_, right? I mean, this is my first real party, but that doesn't mean a thing these days. I read once that parties were invented way back—"

"Casey," a voice behind her drawled. "You're boring the guests. So shut up."

A deep feeling of annoyance surged in her gut (or were those butterflies in her stomach?), and Casey turned around to face her step-brother. "Fine," she spat, irked for no particular reason. "What do _you_ suggest?"

Derek tilted his head to one side, pretending to consider the question. "Hmm… how about…. Neither?"

Casey threw up her hands, causing the cardigan to fall off its hanger. "I give up!" she groaned. "I'm just not cut out for this kind of thing! We're leaving in 45 minutes and I haven't even started to do my make-up yet!"

"Yeah, well, at least your hair is done," Derek snickered, eyeing the wild tangles that frizzed around Casey's head. She fumed up at him and shoved past, heading for her bedroom. He followed her like a puppy that just wouldn't learn when to quit.

"Shut up, Derek! You're not helping, so either give me a hand or go away!"

There was a pause, and for a moment she thought he'd actually gone away. Then, she felt him come stand right behind her – she heard him breathing just behind her left ear – and he said, "Why don't you wear the pink sweater and those dark jeans that I told you about? You know, that evening that we—we had our lessons?"

She froze, instantly feeling a shiver dance down her spine and along her arms at the memory of their first kiss. It had been so sudden, yet so passionate. She rubbed at the skin on her arms and turned around. "O-ok. Thanks, Derek."

He leaned in close, smiling mischievously. "Do you need help putting that sweater on?" he whispered in her ear. Casey's knees trembled, and she was about to clutch at Derek to keep from falling when a voice from the doorway interrupted.

"What's going on?" Victoria asked. "What are you doing, Derek?"

He sprang away from Casey and spun around. "Just giving her bad advice about her wardrobe. Unfortunately, she decided already, so I was too late."

"Oh. Well, then come help me decide which eye shadow to use!"

Victoria pulled Derek away. Casey rolled her eyes to herself and continued to get ready. She lifted the pink sweater off its hanger, feeling its soft material and breathing in the scent of Derek that still clung to its threads….

--

The party was raging by the time they arrived. Looking through one of the front windows, Derek had never seen so many people packed into one place, and he'd been to his share of parties. He'd never figured that so many people knew who Ralph was. He turned around and eyed the girls who stood behind him. Victoria looked glamorous in a turquoise dress with blue flowers all over it; her hair was loosely curled and her eyes were lined with lots of make-up. Casey, on the other hand, looked much more subtle. She wore the outfit he'd suggested and had pulled her hair half-back, and straightened the rest. Her face had make-up on it, but it looked much more natural than her cousin. Both looked very hot, and he had a feeling that all the guys would think so, too.

As for his own style, he'd adorned a long, button-up brown shirt (with the sleeves rolled up to his elbows) and stylish jeans. He hadn't spent much time on his hair (other than to put on some mousse so that it looked straighter).

"Ok, girls, listen up," Derek told them as they stood on Ralph's front porch. "You need to stick close to me, ok? I don't want you getting lost in this madhouse. And Casey, _please_ try not to trip or spill anything all over yourself (or me, for that matter). Got it?"

"Yes," she growled, and shoved past him to open the door. He quickly followed her inside.

People were everywhere. He had to shove against their sweaty, gyrating bodies to even make it across the room as he trailed Casey. She seemed to be searching for someone; he narrowed his eyes and wondered who it could be.

"Hey, man!" Sam's voice shouted over the music and noise of the party. "How's it going? Who's the lady with you?" He approached Derek and Victoria.

"This is Casey's cousin, Victoria. She's visiting us for the weekend."

"Ah, great to meet you," Sam smiled warmly and shook her hand. "I'm Sam, Derek's best friend."

Her eyebrow went up. "Ohhh," she replied. "You're the infamous best friend, eh?"

"Victoria," Derek interrupted before she could say anything more on the subject, "Let's go find Casey. This is her first party, and knowing her she'll end up being trampled by someone."

Victoria sighed loudly and waved a hand in dismissal. "Oh, let's just dance, Derek. Sent the ex after the klutz. I want to enjoy myself." And she grabbed him and pulled him to where everyone else was dancing.

Derek considered protesting. He considered withdrawing himself from her grasp and just walking away. Hell, he even considered shoving her off of him and yanking Casey out the door.

But he had a reputation to withhold. He was, after all, the infamous Derek Venturi. He couldn't let some stupid klutzilla stepsister of his interfere with the way his world went around. He'd already let her tilt things off kilter enough as it was.

So he took a breath and decided from this moment on to enjoy himself. He would dance with Victoria, and he would _like_ it. Casey could do what she wanted to; starting now, he didn't care about her anymore.

--

Casey felt slightly nauseous. She gasped, feeling as though there wasn't enough air in the room for her, wasn't enough room to even breathe. She'd managed to separate herself from Derek and Victoria, and now she felt a bit wary of her eagerness in coming here. She'd been hoping that she might have had a chance to teach Derek a lesson or two about chivalrous dating, but… that didn't seem likely now.

Swallowing her fears, Casey stood up straight and resolved to find her way to the stairs. She would then wait there until Derek and Victoria finally realized she was gone… or until she saw them stumble out the door (probably making-out as they did so). Once she reached the stairs, she noticed that Derek and Victoria were dancing together – and seemed to having a great time. Apparently she'd been right when she'd thought that they'd forget about her. Casey narrowed her eyes and leaned further over the railing. Well, _fine_. If that was how they wanted to play, she would make them regret it. Derek might be a cocky bastard sometimes, but her own _cousin_ should at least pretend to care about her! She looked around, hoping to see a familiar face… or something to inspire her to think of a prank.

Instead, she realized that a girl was standing in the entryway, chatting animatedly and saying the name "Derek" several times in a row. Was that… she squinted and took a couple of steps down. It was! It was a girl from school that Derek had dated for a short while, shortly before he'd shared his knowledge of flirting and all that with Casey just a few days ago.

"…and Derek promised me that he'd take a raincheck on our date last week, so we're going to Smelly Nelly's on Thursday now, instead," the girl was saying.

Casey gasped, opening her mouth in shock and outrage. Was Derek actually still _with_ this girl? What was her name again? Danielle? Had he rescheduled his date with her on the very night he'd been making out with her, _Casey_?

The girl bounced through the crowded entryway and into the living room, somehow managing to look graceful and poised as she was jostled by several people.

"Der-EK!" Casey hissed to herself, crossing her arms and narrowing her eyes in fury. "Oh, you are SO dead!"

She pushed down the stairs and followed Danielle to the living room. The girl must not have noticed him because he was still dancing with Victoria. Casey marched (if one could call it that with so many people) over to the dancing couple and shoved Derek in the arm.

"Hey!" he cried, automatically shoving her back. "What was that for, klutzilla?"

"You're dating that Danielle girl!" bellowed Casey.

"Yeah, so? I'm just dancing with Victoria, we aren't exactly doing anything wrong," he shouted back.

"You were still dating her when you kissed me last week!"

Immediately, Casey realized what she'd just said, and put her hands over her mouth and jerked her head to look at Victoria. Her cousin's eyebrows were raised and her mouth was slightly open. It seemed like this piece of news had shocked even _her_.

"I would never do that!" Derek hissed, grabbing Casey's upper arm in a grip so tight it was starting to hurt. "I'd rather kiss that stupid, blathering Danielle girl than even so much as look at you in that way!"

Casey felt tears prickle at the corner of her eyes, and Derek let go of her arm quickly, as though he felt disgusted by their touch. No one said anything after that for a moment. However, Victoria recovered quickly, and barked out a chuckle. "Oh my God. Are you _serious_, Casey? Why would Derek ever want to do that?" She looked at Derek, and her amused expression faltered. Casey followed her gaze, and realized that Derek was giving his stepsister a glare that would scar children for life.

"Wh-what?" she stammered. Then she noticed that Danielle was standing besides her. And apparently had heard everything he'd just said about her, because she looked both livid and hurt.

"How _could_ you, Derek?" she screeched, huge tears trickling down her cheeks. "We're _through_!" And with that, she shoved past them, hitting Derek's shoulder on the way.

"Oh…" Casey said after the girl had left.

"Yeah, _oh_." Derek shook his head, and groaned in aggravation. "I don't get you, Casey. Why can't you just stay out of my business? Why did you make me drag you to this stupid party? Everything would have been fine if you had just stayed in your room and done your homework like the keener you really are!"

At his words, all sadness seeped out of Casey, and she felt anger surge inside of her chest as her adrenaline kicked in. She practically growled at him as she said, "Well, excuse _me_, Derek Venturi, for actually _caring_ about what happens beyond the world of high school! And I may be a keener, but at least I'm not a rude, selfish pig like you are!"

"Casey," Victoria said, stepping in front of her cousin, "Chill, ok? Follow me upstairs; we'll find a place for you to calm down."

Nodding, Casey pressed her lips together in one final scowl at Derek, and turned on her heel, shoving her way to an upstairs bedroom. The quiet there was still broken by the booming base of the stereo, but at least there weren't tons of people, and it wasn't quite so loud. Casey breathed a sigh of relief, grateful to Victoria for actually doing something considerate.

"So," Vicky said crisply, "Let's get some things straight here. One: you have the hots for your stepbrother." Casey started to protest, but Victoria held up a hand. "I would find that utterly disgusting if he didn't happen to be my stepcousin." She paused, a smirk appearing on her lips. "He certainly was a great kisser. God, he certainly knew where to put his hands…" At Casey's face, she rolled her eyes. "Oh come on. It's obvious that Derek's been around and gotten some experience." She gave a little sigh of exasperation and raised an eyebrow at Casey. "_You_, on the other hand, are hopeless.

"Now," she continued, "Two: _I_ like Derek. And _I_ get Derek."

"What?" cried Casey. "Wh-what are you talking about?"

"I know you like the guy. Don't blame you for it. But unless you want me to tell your parents that you two had a little make-out session, or whatever it was that you did, then you better listen up." Victoria sat on the bed and faced Casey directly, looking very solemn. "Derek's _mine_, you hear me? So you better not so much as _look_ at him until I'm gone, ok? And every other time I come to visit."

"Well," Casey said, "You can have him. I wasn't thinking straight when I… said what I did about…."

"Yeah, ok." Victoria examined a nail. "Well, I'm going back to find Derek. Have fun being lame here by yourself. Although," she added, "if you want to be useful, go get me some punch and bring it back here. And get Derek, too. I'm going to have some fun with your stepbrother, teach him what us _experienced_ girls know."

Casey resisted the urge to spit in Victoria's manicured face. "Get your own punch, _Vicky_. You can't order me around."

Victoria stood up, hands on her hips, and narrowed her eyes. "I'll do what I damn well please, _Casey_, and you better listen to me, or I'll tell Aunt Nora all about your little rendezvous with Derek."

Casey gulped. "Fine," she replied. "What flavor do you want? Watermelon?"

Victoria gloated, smiling and turning her nose up at her cousin. "Fruit punch, Casey. Only a keener would think people actually served any other flavor. Now get out so I can prepare myself for Derek's entrance."

--

A hand shoved something at him, and Derek hastily grabbed the punch-filled cups before they spilled all over him. "Hey!" he shouted, "Watch it—" He paused, seeing who it was, and rolled his eyes at Casey. "What are you doing, coming near me?"

"Victoria wants you," Casey deadpanned at him. "She's upstairs, second door on the right."

He stared at her. "What?"

"Vicky wants to teach you a little lesson about the art of making out with _experienced_ girls," Casey spat, looking quite annoyed as she scowled at the cups in his hands.

"Oh, well… I don't want to. Not if she thinks she can order me around."

"Join the club," Casey responded. "She told me that if I didn't do exactly as she asked," Casey paused, looking around nervously, before continuing, "she would _tell_ on us for kissing. You know, since we're _stepsiblings_." Her eyes grew wide and she looked pale. "Maybe it's _illegal_ or something…." Derek made a face; it looked like she was going to hurl.

"It's not illegal," he said, although he knew no such thing. He sure hoped it wasn't… Why would it be?

"Well, doesn't matter. We certainly don't want George and Mom knowing, so let's just do what she says," Casey said.

"Look," Derek replied, taking a swig of the punch. "Let's just ignore her. Maybe she's just threatening _you_. Just go upstairs and tell her I won't come."

Casey shook her head, tendrils of hair going back and forth from the movement. He wondered why he'd been revolted by her just a few moments before… His stomach clenched and Derek gritted his teeth, hoping the physical feeling deep inside of him would pass. Soon.

"We can't do that," Casey said, pulling on his arm. Derek let her drag him upstairs. "She'll get mad."

"All right, all right. I'll go in and have a word with her." He approached the door, then turned around and faced Casey. "Wanna give me a good luck kiss?" he whispered in her ear.

She raised her eyebrows. "Didn't you just say you thought I was a total loser? Aren't you risking _everything_ by being near me right now?"

Derek grinned down at her. "Oh, come on, Case. What have I always said about living dangerously?"

Her lips tugged upwards for a moment, and then she broke into a grin. "Yeah, yeah, yeah."

And she stood on tiptoe to kiss him, pressing her mouth to his for a brief moment, before pulling away. "Now, get in there."

He shook his head. "Oh come _on_," he drawled, setting the punch glasses down on a nearby table. "Is that the best you've got?"

"Not at all," she replied, rolling her eyes. "But, in case you hadn't noticed, we're at a party, with lots of people everywhere!"

"Well then, care to reinact your first party? Bathroom's right behind you. You could pretend to lock us in again, like last time, so you could be stuck in a small space with me."

Casey put her hands on her hips and glared at him. "I did _not_ pretend to lock us in!" she fumed. "_You_ were the one who couldn't figure out how to fix the lock!"

Derek waved a dismissive hand. "Whatever, Casey, you wanted me then, and you want me now." He took a step closer. "So let's just take a moment to finish what we started in that bathroom, eh?"

Before she could protest, he shoved her into the tiny room. It only had room for a shower, toilet and small counter. "Well," Derek drawled. "Should we do this in the shower or on the counter? We could find a way to make things work with the toilet, but I say the counter is our best bet…"

"God, you're such a guy," Casey replied, shoving his shoulder playfully. She picked up a shampoo bottle. "So maybe I should squirt you with this? You know, to get the full effect from last time?" She aimed the nozzle at his face.

Derek grabbed it from her. "Yeah," he replied, "I don't think so."

"You prefer toothpaste, Derek?" Casey made a face at him. "I thought you hated brushing your teeth."

"Haha," he responded. For once, he wished she'd just shut up and make out with him already. He had always secretly enjoyed their banter, but his body was starting to get the better of him now. He couldn't stop staring at the way that pink sweater clung to her chest, or how her jeans were slung low on her hips, revealing a strip of pale skin above the hem. Maybe she'd let him take the sweater off this time, if he was patient and took things slowly at first. Maybe she'd even—

He was interrupted from his thoughts as a jet of cold liquid squirted him directly on the mouth.

"The hell!" he garbled, spluttering the bitter tasting shampoo from his mouth.

"That'll teach you to _listen_ to me, Derek!" Casey cried. "Lesson number 1: _always_ treat a girl like a human being, and _don't stare at her boobs_, you jerk!"

"I wasn't staring at your boobs!" Derek protested. At the look on Casey's face, he amended his words. "Well, not for very long!" She still looked livid. An idea came to him, and he soothed, "If it makes you feel any better, you have better boobs than Victoria."

Casey's face relaxed slightly, and she even lowered the shampoo bottle that she'd held poised at Derek's face. "Really?" she asked, looking pleased.

"Really."

"Huh. Well, in that case—hey!" Casey spit out a mouthful of toothpaste that Derek had just squirted into her mouth. "De-REK!"

He burst out laughing and squeezed the tube again. Blobs of toothpaste landed on her sweater. "Guess you'll have to take it off and wash it in the sink!" he chortled.

Her response was to send another jet of shampoo at his face. Soon, they were slipping and sliding on the tiny bathroom floor, much like the first time they'd been in this situation. Except that this time, the floor was much smaller, and so when Casey slipped on the spilled shampoo on the floor, she knocked Derek over, too, and he landed halfway in her lap, laughing.

"Get off of me!" Casey tried to yell, but her own laughter prevented it from sounding very threatening.

"But, Casey," Derek protested. "I've learned my lesson about treating girls with respect. I think I should get a treat. Just a teensy, eensy one?" he added after she raised an eyebrow at him.

"Fine," she quipped. "But just a teensy, eensy one, all right?"

…………………

A/N: Sorry it isn't quite finished yet. I've been pretty busy this week, which is why I suck at updating. And since I'm going away this weekend (and won't have time to work on this story), I figured an incomplete chapter update was better than none at all, right?

So yeah. Sorry again, guys!! I promise I'll get the rest of this chapter up (as soon as I finish writing it!) :)


	5. Chapter 4 and a half

Lessons in Love: Respect and Responsibility

Lessons in Love: Respect and Responsibility

A/N: Wow. Epic fail on my part about the updating. Sorry guys! August is seriously busy for me, so that's the reason for my not updating in over a week. hangs head And wow, did I make Derek a little bitch in that last part of chapter 4… hmm. I'm gonna tone it back from now on, lol.

Chapter 4.5

….Casey spit out a mouthful of toothpaste that Derek had just squirted into her mouth. "De-REK!"

He burst out laughing and squeezed the tube again. Blobs of toothpaste landed on her sweater. "Guess you'll have to take it off and wash it in the sink!" he chortled.

Her response was to send another jet of shampoo at his face. Soon, they were slipping and sliding on the tiny bathroom floor, much like the first time they'd been in this situation. Except that this time, the floor was much smaller, and so when Casey slipped on the spilled shampoo on the floor, she knocked Derek over, too, and he landed halfway in her lap, laughing.

"Get off of me!" Casey tried to yell, but her own laughter prevented it from sounding very threatening.

"But, Casey," Derek protested. "I've learned my lesson about treating girls with respect. I think I should get a treat. Just a teensy, eensy one?" he added after she raised an eyebrow at him.

"Fine," she quipped. "But just a teensy, eensy one, all right?"

She stood on tiptoes and wiped a blob of shampoo off of his cheek, then leaned closer, closing her eyes as she felt his breath on her cheek, his lips opened to meet her own….

"Are you _kidding_ me, or something?" a shriek came from the doorway. Victoria was standing there, looking angrier than Derek imagined she'd ever been. He and Casey quickly jumped away from each other.

"Victoria, it's not, it's not what it looks—" Casey stuttered.

"Oh, it looks to me like you were just about to kiss Derek and completely disregard what I told you! He's _mine_."

"Hey, hey!" Derek interrupted, growing angry at the way Victoria was speaking to Casey and what she was saying about himself. "Calm down, Victoria. Casey was only giving me a good-luck kiss on the cheek before I met you in Ralph's bedroom. That is where you were waiting, right?" Derek sauntered over to her and pressed his mouth to hers, long and deep. He pulled away, plastering a grin on his face.

Victoria blinked, her eyes cloudy from the kiss. "Well, I guess so. I mean, it was a bedroom, with lots of… stuff in it."

Derek saw Casey roll her eyes. "I brought you the punch, but I think I must have spilled it, or left it somewhere. Do you want me to get some more for you?"

"No, no. Just… go away." Victoria wrapped her arms around Derek's neck.

Heaving a huge sigh, Casey met Derek's eye and mouthed, "What are we going to do?" He made a face, just as baffled as she was. This definitely sucked.

--

"And then, when I played the last beat in the song, the audience got up and cheered! Isn't that awesome, man? Uh, I mean… woman?"

Casey forced a smile at Ralph. In any other situation, she would have found him endearing, but she was way too stressed out. She had ventured downstairs and collapsed on a random couch in the least-crowded area of the house. Ralph had soon found her, and was dismayed that she didn't appear to be having any fun. He'd then decided to sit down and cheer her up (throwing in a few flirty comments as he did so).

"You know," Ralph continued, "You look really great with that sweater. I love the beads all over it. I pretty much love patterns in general."

"Beads?" Casey crinkled her brow. "Oh!" she exclaimed, realizing that he meant the toothpaste that Derek had gotten all over her. "Actually, they're globs of toothpaste."

Ralph grinned, nodding. "Right on! Way to rock the new styles."

"Uh, thanks." Casey sighed.

"What's wrong?" Ralph asked, looking even more concerned.

Casey sighed again. She debated just telling him everything was fine, or that she was tired, but for some reason, his innocent and genuine concern encouraged her. She blurted out everything to him, right then and there, from the first moment that she kissed Derek, right up until Victoria found them in the bathroom and forced them both to bend to her will.

When she had finished, Ralph looked very serious (the first time Casey had ever seen him look like that). He didn't respond for a moment, his eyebrows furrowed in thought.

"You know, Casey," he said at last, "This is a tough situation." He paused, then continued, "But I think the best thing for you to do is to fight back. Teach her that she can't control you both like this."

"But _how_ can I do that?" Casey cried. "She'll just tell my mom and George what's been going on!"

"Beat her at her own game," Ralph replied. "Make her feel like the _real_ loser is _Derek_, not you. Because, let's face it…" Ralph's goofy grin returned, "it's the truth."

As the words left Ralph's mouth, Casey realized just how brilliant Derek's silly friend was. "Ralph, you're a mastermind!" She hugged him in glee, almost bouncing off the walls to jump-start his idea.

"Thanks, Casey!" he responded, still grinning. As she leapt up to go remind Derek and Vicky that they "had" to leave (it was pretty much curfew, right?), Ralph called, "By the way, what's a mastermind?"

Casey didn't even have time to chuckle. She was already half-way up the stairs.

--

A/N: Ok, sorry that last part was so short. It _was_ a really long chapter! It's getting late though, and I was super tired today, so I'm just gonna head to bed. Hope everyone's having a great summer! Again, sorry for bitchy!Derek. Just pretend he was never that extreme. :)


	6. Chapter 5

Basic Ideas for Casey to make Derek do:

Lessons in Love: Respect and Responsibility

A/N: Here's chapter 5! Just to let you know: fluff abounds at the end of the chapter! You've been warned. ;) Anyway, hope you enjoy.

Chapter 5

"Victoria. Derek," Casey said, shoving open the bedroom door that she noticed the two of them enter earlier. The sight before her brought her up short: seeing Victoria nestling her body against Derek's as they lay sprawled out on the bed, Casey forced down a groan of disgust. She had to be professional about this. "Time to go."

"What are you blabbing on about?" Vicky asked, pulling her mouth away from Derek's.

"I said, 'It's time to go.' Derek and I have a curfew set for… uh…" Casey quickly glanced down at her watch. "Uh… ten thirty." She grimaced, wishing it had been a bit later.

"Seriously?" Victoria raised an eyebrow and brushed her hair out of her face. "Wow, I didn't realize how lame you guys have it at the Venturi-McDonald household."

"Yeah," replied Derek, quickly catching on, "George's really gotten tough on me after Case's mom moved in. Pretty annoying, huh?"

"I'll say." Victoria got up and started looking around for what Casey could only guess were her shoes and shawl. Meeting Derek's eyes, Casey gave him a little smile as he mouthed the words, "_Thank you_," at her. She mouthed back, "_No problem_." His own lips tugged upwards slightly in a return smile.

"So, Derek, your dad picking us up again?"

Casey froze. _Crap_, she thought to herself. George had dropped them off, promising to return at eleven pm sharp. She'd completely blanked that fact. _Now what?_

"Uh, no," Derek replied smoothly. "We're supposed to take the bus home."

Victoria's mouth actually dropped open. "The _bus_?" she gasped. "With all the creepy homeless people and hygienically-challenged guys? I'll probably be sexually harassed!"

"You'll be fine," Casey snapped. "We ride it all the time."

"God, all right, all right," Vicky relented, seeming to be caught off-guard by Casey's sharp anger. "Just let me freshen up in the bathroom first." She trudged into the hallway in search of a mirror.

Casey rolled her eyes. "Why am I related to that monster? I thought she was rattling on and on about getting too _much_ attention on the bus. Does she expect that 'freshening up' will reduce that, or something?"

"Hey," Derek held up his hands. "Your family, not mine. Don't ask me to delve deep into her brain. I've gone far enough down her throat already." He shuddered.

"Ugh, gross, Derek," Casey said, sticking out her tongue in disgust. "But ok, listen up," she continued in a whisper, grabbing Derek's arm and pulling him as far from the door as possible. "New plan: we can't have her ordering either of us around anymore this weekend, right?" At Derek's enthusiastic nod, Casey went on, "So I was thinking (with Ralph's help): what if we—"

"Wait a minute," interrupted Derek, "You got _Ralph's_ help? Why the hell would you do that?"

"He had some good advice," Casey grumbled. "Shut up and listen!"

"Ok, ok. But… wow. I never thought you'd refer to good advice and Ralph in the same sentence…."

"So he and I _decided_," Casey cut him off, shooting him a look, "that we need to make you less appealing to Victoria. That way she won't have any desire to exchange any more saliva with you."

"Sounds good to me," Derek said. "But there's just one problem with that." He put a hand on his chest. "How do you make Derek Venturi _un_appealing?"

Casey let out a frustrated groan and shoved Derek onto the bed. "Could you be any more conceited?"

"Hmm," Derek mused, sprawling out over the quilt. "Nope."

"Well, we'll work the details out later. I have a feeling it won't actually be very difficult." Casey paused. "The question is, how do we make her stop bossing _me_ around?"

"Well, maybe we could make you unappealing, too. Then she'd be freaked out that your grossness would pollute the air around her. Oh wait!" Derek exclaimed, snapping as if he'd just thought of something. "I forgot. You're already disgusting!"

Casey narrowed her eyes, wailing "De-REK!" He just laughed.

"Okaaaaay!" Victoria's voice shrieked from the doorway. "I'm readyyyyy!"

Derek jumped up. "Right. So you're familiar with the bus system then?"

Vicky rolled her eyes. "Not really. I don't believe in interacting with the people who use it."

"Oh. Well, I use it all the time."

Casey bit back a smile. Derek was really getting into this.

"Oh?" Victoria raised her eyebrows and gave Derek a once-over, as if he might be infested with fleas. "Well, I'm sure you'd avoid it if you could."

"Nah," Derek waved a hand in dismissal of the comment. "A lot of my buddies ride the bus. One guy lives in cardboard boxes and gives me free lint every Thursday. He's a great guy. I think his name was Guster."

Victoria looked horrified. "Well, let's just hope he's not there tonight."

"Yeah," Casey chirped up, an idea popping into her head. "Derek and I take the bus home from school a lot, since we only have one car, and we've met all kinds of people there. Derek's best friend (and my ex-boyfriend), Sam, is actually the second cousin of Guster. He got ran away from home and has been living under a bridge. He bathes in the river, so he never smells."

"Ya gotta love Sam," Derek sighed, grinning. "I _love_ how resourceful he is, not wasting water for long, hot showers. I've bathed in that river a couple of times myself!"

Victoria stared at them both, open-mouthed. "Are you guys just fooling around with me?"

"What?" Derek gasped, pretending to look hurt. "Are you… are you grossed out by me? After that hot make-out session we just had?" He hung his head, and Casey had to give him credit for how sad he looked. "Do I… do I smell bad or something?"

"No, no!" Vicky reassured him. "You smell fine. I just never knew that you spent so much time with… homeless people."

Derek nodded, pretending to brush away a tear. "No one seems to realize how incredibly interesting they can be." Casey resisted the urge to roll her eyes. She couldn't believe Vicky was actually _buying_ Derek's charades.

"Well, in that case…" Victoria still sounded doubtful, "I guess we'd better get going then. But if anyone makes a move on me, I swear to God—"

"Oh, I'll just call George," Casey cut in. "I don't want to make you uncomfortable, cuz."

"Well… If you're sure he won't mind…" It was almost laughable how hopeful Victoria looked.

"Nah, he's probably still up," Derek said. "I'll go find my coat; my cell phone's in the pocket. Oh crap, Case, where did we leave the coats?"

"Hmm, I think they're downstairs. We better go grab them. Wait here, Victoria." Casey winked at Derek. This was almost fun!

"I'm coming with you!" Victoria said. Thinking fast, Casey opened the door a bit. "Oh, hey Sam!" she cried, seeing him walking up the stairs with Ralph. "Come say 'hi' to Victoria again, and tell her all about your time living under the bridge!"

Derek came to stand behind Casey and opened the door wider. "And don't forget about the part where you got attacked by leeches while bathing in the river! That was so funny!"

"Um…" Victoria suddenly looked very pale. "I think I'll just wait in here while you guys go get those coats. Come get me when you're done!"

Casey and Derek assured her they would, then left and closed the door, barely suppressing their laughter.

"Uh," Sam mumbled, "What was that about me bathing in rivers with leeches?"

Casey exchanged glances with Derek and felt a wave of giggles threaten to overtake her. Derek, however, didn't have so much self-control. A loud snicker filled the air. Casey hiccupped in her attempt to subdue her own snickers. A moment later they were clutching at Sam, laughing until their sides hurt.

"Uh…" Sam turned to Ralph. "Do you have any idea what they're talking about?"

Ralph beamed. "I think that one of my ideas finally made sense!"

--

"And so my dad'll be here in about ten minutes," Derek finished telling Victoria. He and Casey were sitting next to her on the bed, having gone downstairs for their coats and pretending that they'd just called Derek's dad, before coming back upstairs to find her.

"Did you have a fun time at the party?" Casey asked. Derek looked up and met her eyes, hoping it would trigger a suppressed giggle again. He hadn't realized how much fun it was to conspire against people _other_ than Casey. Of course, it was probably because he was doing it with her as his partner in crime.

Casey did indeed press her lips together in an effort to conceal her laughter. It only half worked.

"Well, I guess it was all right," Victoria muttered, not seeming to have noticed Casey's chuckle. "I mean, I've been to better parties, with less… homeless people in attendance."

"Oh, you mean Sam?" Casey asked. "Well, if it makes you feel better, he never smelled when we kissed." She paused for dramatic effect. "Except like seaweed, actually. Come to think of it, he sort of had a fishy smell too."

"But it was a hot fishy smell, right?" Derek asked, hiding a grin. This was just too much fun.

"Oh, of course. I guess I really just love that outdoorsy type."

Victoria made a face. "Never thought they'd start calling homeless people 'outdoorsy'…"

Derek glanced at his watch. "Looks like dad'll be here in a few minutes. Let's head on downstairs and wait for him on the porch."

The three pushed their way past all the sweaty bodies lining the staircase and made their way outside. The air was cool and refreshing, with a hint of pine to it. Derek inhaled deeply. "I just love this outdoor smell."

"Really?" Casey asked, raising an eyebrow. "I thought you said last week that—" She stopped as Derek gave her a look. "I mean, yeah, of course!"

"Ugh," Victoria looked like the smell might make her vomit. "I hate the smell of the outdoors. Makes my allergies act up."

"Huh. Too bad."

George pulled up at that moment, and the three got in. Derek and Casey made sure to keep up a constant chatter so neither Victoria nor George would have a moment to speak. They didn't want their ploy about normally taking the bus to be ruined by a comment from George or a question from Victoria.

Once they arrived home, George headed downstairs to bed and Victoria claimed exhaustion. When Derek offered to give her a goodnight kiss, she declined, saying that she was just "soooo tired from all the dancing." She paused, and added, "You know what, you two? Just forget all about our little 'bargain'. You guys can make out all you want to… you obviously deserve each other… swimming in rivers and dating guys with leeches and all that…" Victoria gave a shiver of what could only be disgust. "I really have no desire to ever speak to either of you again."

As she retreated up the stairs, Derek finally let his grin widen on his face. He met Casey's gaze and felt his insides go all warm as her eyes crinkled with delight. At this, he felt a bit concerned, despite his enjoyment of the latter part of the evening – was he becoming a softie? Had Casey's laughter _actually_ made his stomach flutter?

"Thank _God_ that's taken care of," Casey sighed in relief, then chuckled.

"Yeah, a real load off my back. I'm never making out with anyone from your family _again_." Casey rolled her eyes and playfully shoved his shoulder.

"God, that whole prank we pulled on Vicky was hilarious," she giggled after a moment of companionable silence. "I never knew how gullible Victoria could be."

Derek nodded. "Yeah, she's almost as bad as you are."

Casey stopped laughing and glared at Derek. "Ha ha," she said, rolling her eyes.

"Nah," he relented, "You've got a point. You are by far the most gullible." He sent a mischievous grin at Casey, and laughed as she leaned over to bestow his punishment for such comments: a tickle.

Laughing, he snuck his hand down to the back of her knee, where he knew she was the most ticklish, and soon they were both having a "tickling" war, with Derek as the victor. "I win," he said, laughing at the livid expression on her face.

"No way!" she screeched, trying to get out from under him. He'd pinned her to the couch and was sitting on her knees. Her hands attacked his sides in an effort to make him get off, but he managed to hold his ground. "I'm the winner!"

"Case, you're _pinned_. That's the rule. Even Lizzie says 'Uncle' when Edwin pins her. Just accept it: I _always_ win."

She whacked his legs in annoyance. "That is _so_ not true! I've won many times."

"Name _one_ instance."

Casey paused, biting her lip. Derek tried not to stare down at it, or think about the fact that her knees kept shifting underneath him. "Fine," she snapped. "You win, but only because you cheat."

"But the point is that I always win," he replied smugly, leaping off of her and plopping down into his favorite chair. Not that he minded _touching_ her in certain ways, and in certain areas… but it was too risky out here in the open. He reached to the coffee table, grabbing the remote.

"So," Casey said, snatching the remote out of his hands, "We've got to figure out what all of _this_ is." She waved her hands at the two of them as if it would help them think.

Sighing, Derek wished (briefly) that he wasn't so lazy so he would feel motivated to get up and retrieve the remote control. "How about you quickly teach me a lesson and we head on up to my room for my _reward_?"

Except for a deep flush that rose in her cheeks, Casey ignored his comment. "I can't just go waltzing around school hand-in-hand with you. That's way too weird."

"Agreed."

Casey huffed. "You can at least help me think of how to define our relationship!"

Derek stifled a yawn. "Well, _you_ can think all you want. I'm going to take a nap."

"De-REK! It's 11:20 at night! You can't take a nap now!"

"I can do whatever I want," he replied, settling back onto the recliner. He closed his eyes, half-wondering if she would do anything. Another _huff_ of annoyance came from his right, and Derek chuckled to himself. He _loved_ torturing her. It was almost too easy sometimes.

"Didn't you even have a little bit of fun tonight? What with tricking Victoria and all that?" he heard her demand.

Not bothering to open his eyes, Derek drawled, "Eh. It was all right, I suppose. Better than sitting around at home playing video games with Edwin."

"De-REK!" Derek opened his eyes, and saw that Casey was glaring at him. Suddenly, she reached over and jabbed her fingers into his ribs, in an attempt to beat him at the tickling game that he'd already won. "What the heck, Casey? It doesn't work if you attack me!" He cringed away, wincing as her fingers dug into his skin.

Casey laughed, although it had an edge to it. "Well, good. You deserve some pain after all you put me through tonight. How could you make those accusations about me?"

Derek sighed loudly. "Can't we just pretend that never happened?" At the look on her face, he held up his hands in surrender. "All right, all right. I'll just say that I… I might have been a bit… _annoyed_ at the entire situation, what with your cousin practically making me her sex slave," —Here Casey made some sort of aggravated noise at the phrase, but Derek chose to ignore this— "to you accusing me of making out with you and cheating on Danielle." He paused, and sighed again. "And, I just wanted to say… I'm… I'm sorry, ok? I didn't mean to get so… carried away. I dunno what happened." Derek stopped, unable to continue on and embarrass himself further. He didn't meet Casey's eyes, but he felt the recliner move as she sat on the arm of the chair.

"Sounds like Derek Venturi has a conscience after all," she said, beaming.

"NO," he snapped, nervous that she might be getting the wrong idea. "It's not that, it's just that I didn't want to—"

"Derek," interrupted Casey. "Shut up." At this abnormal comment from Casey, Derek looked up and met her eyes. She was grinning smugly. "You've just learned lesson number 3: acknowledge your mistakes. Especially when your girlfriend's right."

"Wait… we're not girlfriend and boyfriend."

"How about… friends with benefits?"

He snorted. "We're definitely _not_ friends."

Casey narrowed her eyes in a mischievous grin. "Ok then. How about _enemies_ with benefits?"

Derek paused. He could go with that. Holding out a hand for her to shake, he grinned back and said, "Sounds like a good idea. For an amateur, that is."

She rolled her eyes. "So what does that make me then?"

"I guess you'd be the tutor this time." He laughed at her smug look. "So, Case, what's my reward for good behavior?"

"This." She slid down onto his lap, and Derek could have sworn that her eyes smoldered and made his heart skip a beat. Yes, Casey McDonald's eyes _smoldered_ and Derek Venturi's heartbeat _faltered_. Even Derek (who'd been around the block or two when it came to flirting with women) had trouble accepting this idea.

And then Casey kissed him. It wasn't tender or long or soulful. Yet it wasn't rough or short or shallow, either.

No, this kiss was just right. The way her hand crept up to tangle in his hair, the shivers that ran down his spine as she shifted her body in his lap, the feeling of her mouth (full and warm and persistent) against his own, until he opened his lips and then he stopped _thinking_ about how he felt (he really couldn't remember how to think by now anyway) and just started _feeling_.

And even though part of him knew that this _thing_ that was going on between them was some sort of warped, twisted jab at him for flirting with too many girls and skipping too many classes and getting in too many detentions… Derek didn't care. And he especially didn't care that what they were doing right now was "forbidden" (_woah, is Casey really allowed to have her hand there? That is _definitely_ forbidden!_); it only made it more appealing for him.

As he slid his hands under her shirt and up the skin of her lower back, removing his mouth from her to kiss her neck (_he was SO giving Casey a hickey!_), Derek couldn't help grinning. Because this was a damn good reward.

At that realization, Derek decided that Casey's lessons in love weren't so bad at all.

The End

(?)

A/N: All right, so that really feels like an ending to me when I was writing it. I think I'm going to call it finished (I might continue it, but it sort of feels finished to me). But I dunno… I guess I'll see what you guys think!

I've got a few other Dasey stories that have been waiting patiently for me to get around to writing them. So let me know if you want more of this one or something new, and I'll think about writing more. :) Thanks everyone!


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